Conventionally, there has been proposed a printer-equipped electronic calculator which can perform such a double-input check that a first input calculation formula was stored, and then the same calculation formula is input once again, thereby checking whether the first input formula is correct or not (for example, Jpn. Pat. Appln. KOKAI Publication No. H08-241285).
In the above printer-equipped electronic calculator, calculation data, which is involved in the first calculation, is not printed. At a time point when the second input of the calculation formula is finished, the series of calculation data is printed. Thereby, even if there is an input error in the first calculation, the correct input content can be printed after the confirmation of the second calculation, and useless printing can be prevented.
In general, a printer-equipped electronic calculator is advantageous in that, each time an operator and an operand of a calculation formula are input, these are successively printed as calculation data, and a calculation work can be performed while the series of input calculation formulae is being confirmed. However, this advantage cannot be obtained, if the calculation data involved in the first calculation is not printed as in the above-described conventional printer-equipped electronic calculator.
Specifically, useless printing cannot be prevented by the printing method of the above-described conventional printer-equipped electronic calculator, in the case of the checking method in which, each time calculation data is input, the input calculation data is confirmed by display or printing, unlike the double-input checking method in which whether an input calculation formula is correct or not is determined by inputting the same calculation formula once again.
The present invention has been made in consideration of the above-described problem, and the object of the invention is to provide a calculation data printing apparatus and a calculation data printing method, which makes it possible to prevent useless printing and to save printing, in a case where calculation data was input and printed and thereafter the input calculation data is corrected (changed).